1. Field of the Invention
The present invention relates to a covering comprising ceramic tiles for wall, ceiling or floor linings, in which the ceramic tiles are provided with an electrically conductive coating or are themselves designed to be electrically conductive, and are connected to incoming and outgoing lines.
2. Description of the Prior Art
European laid-open print 0 157 179 describes a flat ceramic body provided on its side facing away from the visible side with an electrical resistance coating. In order to make it possible to give an optimal design to the radiating surface available on a wall, ceiling or floor surface to be lined therewith, to manage with as few electrical connecting elements as possible and to ensure an even radiation of heat, a tile is used that is pressed out of plastic ceramic starting material, rolled and fired and the electrical resistance coating is designed as a resistance layer made of a material in which non-metallic, electrically conductive particles have a large specific surface and not substantially changing their electrical conductivity in the case of a temperature increase are embodied in a carrier substance that is electrically non-conductive or only poorly conductive, this material being applied in such a way that the resistance coating has even electrical and thermal conductivity. This body is recognizably provided directly on the wall, ceiling or floor surface to be lined, whereby considerable difficulties may arise in particular when floors are being lined. Firstly, once it is selected, a system for heating all or part of the surface of the corresponding limits of the room can no longer be changed when the covering is completed. Secondly, if heated surfaces are covered by carpets, furniture or similar objects in the case of floor coverings, these areas heat up to a particularly high degree since the objects placed on the floor prevent the heat from dissipating to a large extent. The temperature prevailing on the limiting surface of a room, however, can only be regulated in accordance with one selected point on the corresponding limiting surface. Special switching circuits are either too elaborate or cannot be varied. Furthermore, in a large uninterrupted covering on the limits of a room, since it can only be supplied from the edge of the covering, one must use either large wire crosssections with a small operating voltage or, if small cross-sections are selected, accordingly high voltages, which may possibly endanger the persons using the room. If such a covering on the limits of a room is damaged, it is generally impossible, or at least extremely difficult to remove the damage.